Rate of Disappearance of Subcutaneous Vegetable Oil in Normal and Castrate Mice.

Abstract

Physicians and Surgeons, Columbia Cniversity, niid tljc Presbytr ricrii Bospital, N e w Pork City.Among tlie problems of fat nietaholisni so-called simple obesity has long been of interest to physicians. One point of view taken with regard to this condition considers it as merely another example of the operation of the law of conservation of energy. This attitude is, of course, unassailable, since it must lx true that there is a disparity between expenditure of energy and food intake, if fat is to be stored in tlie subcutaneous tissues. At the same time, however, the phenomenon of obesity would appear to contain relationships of a biological nature which are less well defined. In the human subject, for exaniple, obesity occurs with great frequency following certain disturbances of eiidocrinc function, such as nieiiopause, castration, or pituitary disease. No doubt in each instance there is a displacement of the equilibrium between caloric intake and output due to lowering of the total metabolism. But that this is the whole story is not so clear. The rate of deposition or utilization of depot fat and the type of niechanisni calfecl upon for its ultimate disposal both may be influeliced by factors that are as yet poorly understood. The clinical association of obesity with abnornial endocrine function lends interest to this report of an observation which seems to indicate that even in iiorrnal animals there is a relation between sex and the rate of disappearance of an oil injected parenterally.In tlie course of an experinient designed to study the effect of o-amino-azotoluol 011 the liver, the dye was dissolved in corn-oil ( "Mazola") and in jccted subcutaneously into the backs of mice.The mice were of the closely inbred Bagg albino (C) strain and were all about 4 nioiiths old when first treated. They were 60 in number, 30 niales and 30 virgin females, and were maintained on a diet of stock pellets wliich provides all of the necessary vitamins. As far as is known, they were normal aninials. Each mouse received regularly each week for several months 0.